Polymerization catalyst and process

ABSTRACT

A transition metal compound such as titanium tetrahydrocarbyloxides and a metal hydrocarbyloxide compound such as magnesium hydrocarbyloxides are chemically combined to form a first catalyst component which is treated with a second catalyst component comprising an organometallic compound precipitating agent to produce an active olefin polymerization catalyst. High polymer yields are realized per gram of catalyst when the catalyst thus produced is treated with a halide ion exchanging source and used with an organometallic cocatalyst.

This application is a division of my copending application having Ser.No. 175,219, filed Aug. 4, 1980, now U.S. Pat. No. 4,328,121.

The invention relates to a composition of matter, a method of preparingsame, catalyst, a method of producing the catalyst and a process ofusing the catalyst. In another aspect, the invention relates to aparticularly effective ethylene polymerization catalyst and process.

In the production of polyolefins, such as, for example, polyethylene,polypropylene, ethylene-butene copolymers etc., an important aspect ofthe various processes and catalysts used to produce such polymers if theproductivity. By productivity is meant the amount or yield of solidpolymer that is obtained by employing a given quantity of catalyst. Ifthe productivity is high enough then the amount of catalyst residuescontained in the polymer is low enough that the presence of the catalystresidues does not significantly affect the properties of the polymer andthe polymer does not require additional processing to remove thecatalyst residues. As those skilled in the art are aware, removal ofcatalyst residues from polymer is an expensive process and it is verydesirable to employ a catalyst which provides sufficient productivity sothat catalyst residue removal is not necessary.

In addition, high productivities are desirable in order to minimizecatalyst costs. Therefore it is desirable to develop new and improvedcatalysts and polymerization processes which provide improved polymerproductivities.

Many of the prior art catalysts creat serious problems in theparticle-form polymerization processes because the particle size of thepolymeric product is so fine that difficulties are encountered in theseparation and handling of the product; particularly, trouble occurs inthe extrusion and compounding steps involved in producing a commercialproduct. A method has been found now to keep the high activities ofcertain of these new generation ethylene polymerization catalysts andyet produce polymer of sufficiently large size so that theabove-referred to problem is reduced or eliminated completely.

Accordingly, an object of the invention is to provide a catalyst.

Another object of the invention is to provide a polymerization processfor using a catalyst capable of providing improved polymerproductivities as compared to prior art catalysts.

Another object of the invention is to provide a catalyst and apolymerization process which produces attrition resistant relativelylarge as formed polymer particles.

Other objects, aspects, and the several advantages of this inventionwill become apparent to one skilled in the art upon reading thisdisclosure and the appended claims.

SUMMARY OF THE INVENTION

In accordance with the invention, an active catalyst effective for thepolymerization of olefin polymers at high productivity and forincreasing the particle size of as formed polymer which catalyst isformed upon mixing (1) a metal hydrocarbyloxide, preferably magnesium,and (2) a transition metal hydrocarbyloxide (first catalyst component)with a precipitating agent (3) comprising an organometallic compoundsuch as a hydrocarbylaluminum halide (second catalyst component) at areduced temperature below about 25° C., and treating the thus formedproduct with a halide exchanging source comprising (4) a transitionmetal halide.

Further, in accordance with the invention, a method for producing theabove compositions is provided.

Further, in accordance with the invention, a catalyst is provided whichforms on mixing the above composition of matter and an organometalliccompound as a cocatalyst component.

Further, in accordance with the invention, aliphatic mono-1-olefins arehomopolymerized or copolymerized with other 1-olefins, conjugateddiolefins, vinylaromatic compounds, and the like, under polymerizationconditions employing the catalyst described above.

Further, in accordance with the invention, the above-described catalystis prepared by mixing together a metal hydrocarbyloxide compound and atransition metal hydrocarbyloxide compound in a suitable solvent toproduce a first catalyst component solution, the first catalystcomponent solution is heated, cooled, and optionally filtered in orderto remove any undissolved material; a second catalyst componentcomprising an organometallic compound is added at a temperature belowabout 25° C. to the above-described first catalyst component solution ina manner so as to avoid a significant temperature rise in the solutionto produce a solid catalyst in the form of a slurry with the hydrocarbonsolvent; the solid catalyst is treated with a transition metal halide;and the treated solid catalyst is separated from the slurry, washed witha hydrocarbon compound and dried, wherein all the above steps arecarried out in the essential absence of air and water.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is based at least in part on the discovery of anovel composition of matter resulting from the chemical combination of ametal hydrocarbyloxide compound having the formula M(OR)₂, a transitionmetal hydrocarbyloxide compound, an organometallic compoundprecipitating agent, and a halide ion exchanging source, wherein themetal (M) of the metal hydrocarbyloxide compound is selected from GroupIIA and Group IIB metals of the Mendeleev Periodic Table and wherein thetransition metal of the transition metal hydrocarbyloxide compound isselected from Group IVB and Group VB transition metals of the MendeleevPeriodic Table.

Preferably, the present catalyst is formed by using a magnesiumcomponent comprising Mg(OR)₂ in which R is the same or different and isa hydrocarbyl group containing from 1 to about 20 carbon atoms selectedfrom among alkyl, cycloalkyl, aryl, and combinations such as alkaryl,arylalkyl, alkylcycloalkyl, and the like.

Examples of suitable compounds include magnesium dimethoxide, magnesiumdiethoxide, magnesium dieicosyloxide, magnesium dicyclohexyloxide,magnesium diphenoxide, magnesium dibenzyloxide, and the like. Apresently preferred group of compounds are magnesium dialkoxides inwhich the alkyl radical contains from 1 to about 6 carbon atoms. Mostpreferably, magnesium diethoxide is selected because of readyavailability and particular efficacy in the catalyst composition.

The transition metal of the transition metal compound noted above isselected from Group IVB and Group VB transition metals and is generallyselected from titanium, zirconium, and vanadium. Excellent results havebeen obtained with titanium compounds and they are preferred. Some ofthe transition metal compounds suitable for use in the inventioninclude, for example, titanium tetrahydrocarbyloxides, zirconiumtetrahydrocarbyloxides, and vanadium tetrahydrocarbyloxides.

The titanium tetrahydrocarbyloxides are the preferred titanium compoundsbecause they produce excellent results and are readily available.Suitable titanium tetrahydrocarbyloxide compounds include thoseexpressed by the general formula

    Ti(OR).sub.4

wherein each R is the same as defined above and individually selectedfrom an alkyl, cycloalkyl, aryl, alkaryl, and aralkyl hydrocarbonradical containing from about 1 to about 20 carbon atoms per radical andeach R can be the same or different. Titanium tetrahydrocarbyloxides inwhich the hydrocarbyl group contains from about 1 to about 10 carbonatoms per radical are most often employed because they are more readilyavailable. Suitable titanium tetrahydrocarbyloxides include, forexample, titanium tetramethoxide, titanium dimethoxydiethoxide, titaniumtetraethoxide, titanium tetra-n-butoxide, titanium tetrahexyloxide,titanium tetradecyloxide, titanium tetraeicosyloxide, titaniumtetracyclohexyloxide, titanium tetrabenzyloxide, titaniumtetra-p-tolyloxide, and titanium tetraphenoxide.

Of the titanium tetrahydrocarbyloxides, titanium tetraalkoxides aregenerally preferred and titanium tetraethoxide is particularly preferredbecause of the excellent results obtained employing this material.Titanium tetraethoxide is also generally available at a reasonable cost.

The molar ratio of the transition metal compound to the magnesiumcompound can be selected over a relatively broad range. Generally, themolar ratio is within the range of about 10:1 to about 1:10, however,the most common molar ratios are within the range of about 2:1 to about1:2. When titanium tetrahydrocarbyloxide and magnesium hydrocarbyloxidesare employed to form a composition of matter of the invention, a molarratio of titanium to magnesium of about 2:1 is presently recommended asall the magnesium compound apparently goes into solution easily.

The metal hydrocarbyloxide compound, preferably a magnesium compound,and the transition metal compound employed in the present invention toform the first catalyst component are normally mixed together byheating, e.g., refluxing, these two components together in a suitabledry (essential absence of water) solvent or diluent, which isessentially inert to these components and the product produced. By theterm "inert" is meant that the solvent does not chemically react withthe dissolved components such as to interfere with the formation of theproduct or the stability of the product once it is formed. Such solventsor diluents include, for example, n-pentane, n-heptane,methylcyclohexane, toluene, xylenes, and the like. Generally, the amountof solvent or diluent employed can be selected over a broad range.Usually the amount of solvent or diluent is within the range of about 20to about 100 cc per gram of metal hydrocarbyloxide.

The temperature employed during the heating step can also be selectedover a broad range. Normally the heating temperature is within the rangeof about 15° C. to about 150° C. when the heating step is carried out atatmospheric pressure. Obviously the heating temperatures employed wouldbe higher if the pressure employed is above atmospheric pressure. Thepressure employed during the heating step does not appear to be asignificant parameter.

In addition to the above noted solvents or diluents, more polar solventsor diluents such as nitrobenzene and halogenated hydrocarbons, e.g.,methylene chloride, chlorobenzene, and 1,2-dichloroethane can be used,particularly when producing compositions of the invention having a molarratio of the transition metal compound to the magnesium compound ofother than 2:1. In addition, normal saturated alkanols, such as, forexample, ethanol, n-butanol, and the like, and saturated ethersparticularly saturated cyclic ethers such as, for example,tetrahydrofuran, can be used alone or in combination with the previouslymentioned solvents or diluents in producing catalyst compositionsaccording to the invention. Solvent mixtures useful to help solubilizethe components employed can be readily determined by one of ordinaryskill in the art. Generally, the time required for heating these twocomponents together is within the range of about 5 minutes to about 10hours, although in most instances a time within the range of about 15minutes to about 3 hours is sufficient. Following the heating operation,the resulting solution can be filtered to remove any undissolvedmaterial or extraneous solid, if desired. The composition of matter ofthe present invention thus produced and which is in solution can berecovered from the solvent or diluent by crystallation or other suitablemeans.

It is also emphasized that the compositions of matter of the presentinvention are prepared in an oxygen-free system, e.g., absence of air aswell as a dry system, i.e., absence of water. Generally a dry box isemployed as known in the art to prepare the compositions of the presentinvention usually employing a dry oxygen-free nitrogen atmosphere.

The catalysts of the present invention are made up of two components.The first catalyst component comprises a chemical combination of a metalhydrocarbyloxide, preferably magnesium, and a transition metalhydrocarbyloxide (first catalyst component) and the second catalystcomponent comprises an organometallic compound. Particularly effectivecatalysts have been obtained by treating the above-described catalystwith a halide ion exchanging source, such as for example titaniumtetrahalide. For convenience, the designation "catalyst A" refers tothose catalysts which have not been treated with a halide ion exchangingsource and the term "catalyst B" refers to those catalysts which havebeen so treated. In other words, catalyst B is catalyst A which istreated with a halide ion exchanging source. It has also been founddesirable to employ either catalyst A or catalyst B with a cocatalystcomprising an organometallic compound.

The metal hydrocarbyloxide compounds and the transition metal compoundssuitable for producing the composition of matter of the presentinvention which is used as the first catalyst component of the presentinvention were described above as was the general and specific nature ofthe composition of matter. It is noted that the composition of matter ofthe present invention need not be recovered from the diluent or solvent,such as by crystallation, prior to using such material to produce thecatalysts of the present invention. Good results have been obtained byemploying the first catalyst component solution which was produced whenthe composition of matter was prepared as well as by employingcomposition of matter of the present invention recovered from thediluent or solvent.

The second catalyst component is a precipitating agent selected from thegroup consisting of organometallic compounds in which the metal isselected from metals of Groups I to III of the Mendeleev Periodic Table,metal halides and oxygen-containing halides of elements selected fromGroups IIIA, IVA, IVB, VA, and VB of the Mendeleev Periodic Table,hydrogen halides, and organic acid halides expressed as ##STR1## whereinR' is an alkyl, aryl, cycloalkyl group or combinations thereofcontaining from 1 to about 12 carbon atoms and X is a halogen atom.

Some suitable organometallic compounds include, for example, lithiumalkyl, Grignard reagents, dialkyl magnesium compounds, dialkyl zinccompounds, organoaluminum compounds, etc. The second catalyst componentis generally an organoaluminum halide compound which includes, forexample, dihydrocarbylaluminum monohalides of the formula R₂ AlX,monohydrocarbylaluminum dihalides of the formula RAlX₂, andhydrocarbylaluminum sesquihalides of the formula R₃ Al₂ X₃ wherein eachR in the above formulas is as defined before and each X is a halogenatom and can be the same or different. Some suitable organoaluminumhalide compounds include, for example, methylaluminum dibromide,ethylaluminum dichloride, ethylaluminum diiodide, isobutylaluminumdichloride, dodecylaluminum dibromide, dimethylaluminum bromide,diethylaluminum chloride, diisopropylaluminum chloride,methyl-n-propylaluminum bromide, di-n-octylaluminum bromide,diphenylaluminum chloride, dicyclohexylaluminum bromide,dieicosylaluminum chloride, methylaluminum sesquibromide, ethylaluminumsesquichloride, ethylaluminum sesquiiodide, and the like.

Some metal halides and oxygen-containing halides of elements selectedfrom Groups IIIA, IVA, IVB, VA, and VB suitable for use as the secondcomponent preferably include such as, for example, aluminum tribromide,aluminum trichloride, aluminum triiodide, tin tetrabromide, tintetrachloride, silicon tetrabromide, silicon tetrachloride, phosphorusoxychloride, phosphorus trichloride, phosphorus pentabromide, vanadiumtetrachloride, vanadium oxytrichloride, vanadyl trichloride, zirconiumtetrachloride, and the like.

The hydrogen halides suitable for use as the second catalyst componentinclude preferably such as, for example, hydrogen chloride, hydrogenbromide, and the like.

The organic acid halides suitable for use as the second catalystcomponent preferably include such as, for example, acetyl chloride,propionyl fluoride, dodecanoyl chloride, 3-cyclopentylpropionylchloride, 2-naphthoyl chloride, benzoyl bromide, benzoyl chloride, andthe like.

It has been discovered, however, to obtain an active ethylenepolymerization catalyst for particle form polymerization which producesattrition resistant relatively large as formed ethylene polymerparticles that certain conditions must be employed in forming thecatalyst. These conditions comprise (1) containing the metalhydrocarbyloxide-transition metal hydrocarbyloxide composition (firstcatalyst component) with a precipitating agent (second catalystcomponent) at a reaction temperature below about 25° C. and generallyranging from about -50° C. to about 25° C., preferably from about -30°C. to about 0° C. for a time ranging from about 0.5 hours to about 5hours.

While it may not be necessary in all instances to employ a cocatalystwith the catalyst of the present invention, the use of cocatalysts isrecommended for best results. The organometallic cocatalysts suitablefor use in accordance with the invention are represented by the generalformulas R"'₃ Al, R"'AlX₂,R"'₂ AlX and R"'₃ Al₂ X₃, suitable cocatalystsalso include compounds of the formula R"'₃ Al in which R"' can be thesame as R or can be an unsaturated linear or branched chain hydrocarbylradical of 1 to about 20 carbon atoms. Of the organometalliccocatalysts, the organoaluminum cocatalysts are preferred and inaddition to those described above as suitable for use as the secondcomponent of the catalyst the additional organoaluminum compounds of theformula R"'₃ Al include, for example, trimethylaluminum,triethylaluminum, triisopropylaluminum, tridecylaluminum,trieicosylaluminum, tricyclohexylaluminum, triphenylaluminum,2-methylpentyldiethylaluminum, and triisoprenylaluminum.Triethylaluminum is preferred since this compound produced excellentresults in the runs hereafter described.

The metal hydrocarbyloxide compound/transition metal compound solution(first catalyst component) described above (which is formed bydissolving the recovered composition of matter of the present inventionin a suitable solvent or which is formed initially without recoveringthe composition of matter from the solvent) is then contacted withhydrocarbon solution containing a precipitating agent of the secondcatalyst component at a temperature below about 25° C. A solid reactionproduct is formed which precipitates out of the solution.

The molar ratio of the transition metal compound of the first catalystcomponent to the precipitating agent of the second catalyst componentcan be selected over a relatively broad range. Generally, the molarratio of the transition metal of the first catalyst component to theprecipitating agent of the second catalyst component is within a rangeof from about 10:1 to about 1:10 and more generally within a range ofabout 2:1 to about 1:3 since a molar ratio within the latter rangeusually produces a catalyst which can be employed as an active ethylenepolymerization catalyst.

Since heat is evolved when the first catalyst component and the secondcatalyst component are mixed, the mixing rate is adjusted as requiredand additional cooling is employed in order to maintain a relativelyconstant mixing temperature. It is noted with respect to mixing thefirst and second components that the order of addition is not importantand either component can be added to the other. After completing themixing, the resulting slurry is stirred or agitated for a sufficienttime, generally within a range of about 5 minutes to about 5 hours, toinsure that mixing of the components is complete. Thereafter, stirringis discontinued and the solid product recovered by filtration,decantation, and the like. The product is then washed with a suitablematerial such as a hydrocarbon, e.g., n-pentane, n-heptane, cyclohexane,benzene, xylenes, and the like, to remove any soluble material which maybe present. The product is then dried and stored under dry nitrogen. Theproducts formed in this manner are designated as catalyst A aspreviously described.

In another aspect of the invention, the catalyst, previously designatedas catalyst A, is treated with a halide ion exchanging source such as,for example, a halide of a transition metal in order to produce acatalyst of enhanced activity, referred to previously as catalyst B.Some examples of suitable halide ion exchanging sources are titaniumtetrachloride, vanadium oxychloride (VOCl₃), and zirconiumtetrachloride. Because titanium tetrachloride is readily available andproduced excellent results after extensive experimentation, it ispreferred.

Generally, treating the catalyst with the halide ion exchanging sourcetakes place in a suitable diluent such as a hydrocarbon diluent, forexample, n-pentane, n-heptane, cyclohexane, benzene, xylenes, and thelike, to facilitate the treating process. The treating temperature canbe selected over a relatively broad range and is normally within a rangeof about 0° to about 150° C. The treating time can also be selected overa broad range and generally is within the range of about 10 minutes toabout 10 hours. While the weight ratio of the halide ion exchangingsource to catalyst A can be selected over a relatively broad range, theweight ratio of the halide ion exchanging source to catalyst A isgenerally within a range of about 10:1 to about 1:10 and more generallyfrom about 7:1 to about 1:4. Following the treatment of catalyst A withthe halide ion exchanging source the surplus halide ion exchangingsource (the halide ion exchanging source which is not bound to catalystB) is removed by washing catalyst B with a dry (essential absence ofwater) liquid such as a hydrocarbon of the type previously disclosed,n-hexane, for example. The resulting product, catalyst B, after drying,is stored under dry nitrogen.

It has been found that catalyst B can be stored for a month or longerwithout any significant decrease in activity.

If desired, catalyst A or catalyst B can be admixed with a particulatediluent such as, for example, silica, silica-alumina, silica-titania,magnesium dichloride, magnesium oxide, polyethylene, polypropylene, andpoly(phenylene sulfide), prior to using the catalyst in a polymerizationprocess. While the weight ratio of the particulate diluent to catalystcan be selected over a relatively wide range, the weight ratio ofparticulate diluent to catalyst is within the range of about 20:1 toabout 2:1 and use of a particulate diluent has been found effective tofacilitate charging of the catalyst to the reactor.

The molar ratio of the organometallic compound of the cocatalyst to thetransition metal compound of the first catalyst component is notparticularly critical and can be selected over a relatively broad range.Generally, the molar ratio of the organometallic compound of thecocatalyst to the transition metal compound of the first catalystcomponent is within a range of about 1:1 to about 1500:1.

A variety of polymerizable compounds are suitable for use in the processof the present invention. Olefins which can be polymerized orcopolymerized with the invention catalysts include aliphaticmono-1-olefins. While the invention would appear to be suitable for usewith any aliphatic mono-1-olefin, those olefins having 2 to 18 carbonatoms are most often used. The mono-1-olefins can be polymerizedaccording to the present invention employing either a particle formprocess or a solution form process. Aliphatic mono-1-olefins can becopolymerized with other 1-olefins and/or with other smaller amounts ofother ethylenically unsaturated monomers, such as butadiene-1,3,isoprene, pentadiene-1,3, styrene, alpha-methylstyrene, and similarethylenically unsaturated monomers which do not impair the catalyst.

In one aspect of the invention, the catalysts of the present inventionhave been found to be particularly effective for polymerization ofmono-1-olefins such as ethylene as high productivities have beenobtained and thus mono-1-olefins such as ethylene are the preferredmonomers for use with the catalysts of the present invention.

The polymerization process according to the present invention employingthe catalysts and cocatalysts as above described can be performed eitherbatchwise or continuously. In a batch process, for example, a stirredautoclave is prepared by first purging with nitrogen and then with asuitable compound, such as isobutane, for example. When the catalyst andcocatalyst are employed, either can be charged to the reactor first orthey can be charged simultaneously through an entry port under anisobutane purge. After closing the entry port, hydrogen, if used, isadded, and then a diluent such as isobutane is added to the reactor. Thereactor is heated to the desired reaction temperature, which forpolymerizing ethylene, for example, is, for best results, generallywithin a range of about 50° C. to about 120° C. and the ethylene is thenadmitted and maintained at a partial pressure within a range of about5/10 MPa to about 5.0 MPa (70-725 psig) for best results. At the end ofthe designated reaction period, the polymerization reaction isterminated and the unreacted olefin and isobutane are vented. Thereactor is opened and the polymer, such as polyethylene, is collected asa free-flowing white solid and is dried to obtain the product.

In a continuous process, for example, a suitable reactor such as a loopreactor is continuously charged with suitable quantities of solvent ordiluent, catalyst, cocatalyst, polymerizable compounds, and hydrogen ifany and in any desirable order. The reactor product is continuouslywithdrawn and the polymer recovered as appropriate, generally byflashing the diluent (solvent) and unreacted monomers and drying theresulting polymer.

The olefin polymers made with the catalysts of this invention are usefulin preparing articles by conventional polyolefin processing techniquessuch as injection molding, rotational molding, extrusion of film, andthe like. For example, polyethylene made with the catalysts of thisinvention is typically of narrow molecular weight distribution which isespecially desirable for injection molding applications. Furthermore,the polyethylene produced as described generally has a desirable highbulk density of about 0.44 g/cc as recovered from the polymerizationzone. In addition, the polyethylene produced as described ischaracterized by a high degree of stiffness, e.g., high flexuralmodulus, which is also desirable in many applications.

EXAMPLE I, Catalyst Preparation (Catalyst A)

A stock solution of the reaction product of titanium tetra-n-butoxideand magnesium diethoxide for subsequent use was prepared as follows. Ina dry box, a 10 ounce beverage bottle was charged with 13.25 g (0.0389mole) of the titanium alkoxide and 9.16 g (0.0800 mole) of the magnesiumalkoxide to form a slurry. The bottle was capped, removed from the drybox, and injected with 20 mL of dry n-heptane. The bottle was placed ina bath at 95° C. and the slurry was stirred with continued heating ofthe bath for 21/2 hours. The final temperature was 146° C. The bottlewas removed from the bath, cooled to room temperature and returned tothe dry box where the opaque solution was suction filtered to obtain aclear solution. The stock solution was divided into two equal portionsand stored in glass containers.

Each stock solution was removed in its container from the dry box andtreated with the specified quantity of a solution of ethylaluminumdichloride in n-hexane (1.49 molar) added dropwise for the specifiedtime and temperature to effect the reaction. The bottle containing thesolid particulate precipitate was transferred to the dry box where theprecipitate was isolated by filtration, washed with 100 mL of dryn-hexane, and dried under an argon stream to a constant weight.

The reaction conditions employed and results obtained are given in TableI.

                  TABLE I                                                         ______________________________________                                        Preparation of Catalyst A                                                     Catalyst Designation  A-1       A-2                                           ______________________________________                                        Stock Solution of Mg(OEt).sub.2 - Ti(OC.sub.4 H.sub.9).sub.4                                        17.8      17.8                                          g (calculated)                                                                Moles of Ti(OC.sub.4 H.sub.9).sub.4 (calculated)                                                    0.19      0.19                                          Reaction Conditions                                                           medium used           n-hexane  n-hexane                                      ethylaluminum dichloride (EADC)                                               mL                    57.0      57.0                                          mole                  0.170     0.170                                         temperature, °C.                                                                             25        -20                                           time, hours           4         3.5                                           Wash liquid           n-hexane  n-hexane                                      mL                    100       100                                           Mole Ratios                                                                   Ti(OC.sub.4 H.sub.9).sub.4 /Mg(OEt).sub.2                                                           0.49:1    0.49:1                                        Ti(OC.sub.4 H.sub.9).sub.4 /EADC                                                                    1.1:1     1.1:1                                         Recovered Product                                                             color                 tan-brown brown                                         grams                 7.38      4.87                                          ______________________________________                                    

EXAMPLE 2, Catalyst Preparation Catalyst B

A series of catalysts was prepared from catalyst A-1 and catalyst A-2 bycharging individual portions to green colored 10 ounce pop bottles alongwith 10 mL of dry n-hexane and a magnetic stirring bar. Each bottle wascapped, removed from the dry box and treated with the specified quantityof chloride treating agent (titanium tetrachloride or anhydrous hydrogenchloride) for the specified time and temperature while being stirred.After the treatment each bottle was allowed to return to roomtemperature (about 23° C.) and then returned to the dry box. The solidproduct was recovered by filtration, washed with 100 mL of dry n-hexaneand dried under an argon stream to a constant weight.

The reaction conditions employed and results obtained are given in TableII.

                                      TABLE II                                    __________________________________________________________________________    Preparation of Catalyst B                                                                  Chloride                                                                      Treating                   Recovered                             Catalyst                                                                            Catalyst A                                                                           Agent (CTA)                                                                           Wt. Ratio                                                                            Reaction Conditions                                                                        Product                              Designation                                                                         No.                                                                              Grams                                                                             Name                                                                              Grams                                                                             CTA/Cat. A                                                                           Temp. °C.                                                                    Time, Min.                                                                          Color                                                                             Grams                                                                             Remarks                       __________________________________________________________________________    B-1   A-1                                                                              1.6 HCl.sup.(a)                                                                       --.sup.(c)                                                                        --     25    60    brown                                                                             1.15                                                                              control                       B-2   A-1                                                                              1.6 TiCl.sub.4                                                                        8.63                                                                              5.4:1  25    "     "   1.63                                                                              invention                     B-3   A-1                                                                              1.6 "   "   "      100   "     "   1.98                                                                              "                             B-4   A-2                                                                              1.6 HCl.sup.(b)                                                                       --  --     25    "     lt. tan                                                                           1.26                                                                              control                       B-5   A-2                                                                              1.2 TiCl.sub.4                                                                        8.63                                                                              7.2:1  25    "     tan-br.                                                                           0.94                                                                              invention                     B-6   A-2                                                                              1.2 "   "   "      100   "     "   1.24                                                                              "                             __________________________________________________________________________     Notes:                                                                        .sup.(a) Bubbled in HCl gas. Then flushed system with dry nitrogen, added     about 50 mL of dry nhexane, and filtered off the product.                     .sup.(b) Bubbled in HCl gas as before. Dilution of sample and hexane wash     was not employed.                                                             .sup.(c) A dash signifies no determination was made.                     

EXAMPLE 3 Ethylene Polymerization

A 3.8 liter, stirred, stainless steel reactor was employed for ethylenepolymerization. The reactor was conditioned for each run by charging toit 3 liters of dry n-heptane, closing the port, and heating the reactorand contents at 175° C. for 30 minutes. The reactor was drained andresidual heptane purged with dry nitrogen. The reactor was then closedand cooled under nitrogen pressure.

The conditioned reactor for each run was purged with dry isobutane vaporand 1 mL of the cocatalyst solution containing 15 wt. % triethylaluminum(TEA) in dry n-heptane (0.93 mmoles TEA) was charged followed byaddition of the catalyst. The reactor was closed, about 2 liters of dryisobutane was charged, the reactor and contents were heated to 100° C.and the hydrogen and ethylene admitted to start the run. Unlessindicated to the contrary a run time of 60 minutes was employed.

Each run was terminated by flashing the ethylene and isobutane andhydrogen, if present, from the reactor. The polymer was then recovered,dried and weighed to obtain the yield.

Each polymer yield was divided by the weight of catalyst employed todetermine the calculated catalyst productivity which is expressed askilograms (kg) polyethylene per gram (g) catalyst per hour. In some runsof less than 60 minutes duration, a productivity figure is calculatedfor 60 minutes in which the reasonable assumption is made based on pastexperience that the activity of the catalyst remains unchanged during atleast the first 60 minutes of each run. When the catalyst is diluted, acalculated productivity based on kg polyethylene produced per gramdiluted catalyst per hour is given as well as kg polyethylene producedper gram catalyst contained in the mixture per hour.

The particle size distribution of the recovered polymer ground in aWaring Blender at high speed for 2 minutes was determined by placingabout 100 grams of the polymer on a set of mechanically agitated sieves.The set consisted of sieves (U.S. Sieve Series) having mesh sizes of 30,50, 80, 100, 200, and bottom pan. Agitation was conducted for 15 minutesand the amount of polymer remaining on each sieve and in the pan wasdetermined by weighing. The purpose of grinding the as made polymer isto simulate the attrition polymer particles appear to receive in a largescale reactor such as a loop reactor since polymer particles formed in acommercial reactor are generally finer than those made on the benchscale.

In each run, the initial ethylene partial pressure was 1.4 MPa, theinitial hydrogen partial pressure was 0.69 MPa and the average reactorpressure during the run was 3.59 MPa.

The amount of catalyst employed in each run and the results obtained arepresented in Table III.

                                      TABLE III                                   __________________________________________________________________________    Effect of Catalyst Formation Conditions                                       on Polymer Particle Size and Productivity                                     Catalyst Formation                                                                          Catalyst                                                                             Calculated                                                                           Polymer                                           Run No.                                                                          EADC °C.                                                                   HCl °C.                                                                   TiCl.sub.4 °C.                                                              No.                                                                             Weight Grams                                                                      Productivity Kg/g/hr.sup.(a)                                                         Yield Grams                                                                       Wt. % 50 Mesh                                                                      Coarser Than 100 Mesh                                                                Melt Index                                                                         ##STR2##                                                                           Remarks                 __________________________________________________________________________    1   25 25 .sup.(b)                                                                          B-1                                                                              0.0183                                                                            17.3   317  9.1 54.1   37  22   Control                  2   25 --  25 B-2                                                                               .0171                                                                            32.2   550 14.7 54.3   31  31   Invention                3   25 -- 100 B-3                                                                               .0154                                                                            14.8   228 38.5 76.2    7.8                                                                              33   "                        4  -20 25 --  B-4                                                                               .0155                                                                             8.58  133 75.9 93.3    8.1                                                                              30   Control                  5  -20 --  25 B-5                                                                               .0146                                                                            27.3   398 25.0 72.8   31  32   Invention                6  -20 -- 100 B-6                                                                               .0302                                                                             6.19  187 86.4 97.1   11  35   "                        7  -20 -- 100 B-6                                                                               .0187                                                                             6.47  121 84.9 96.8    4.2                                                                              29   "                        __________________________________________________________________________     Notes:                                                                        .sup.(a) kilograms polymer per gram catalyst per hour                         .sup.(b) dash signifies no determination                                 

Control runs 1 and 4 are included because of U.S. Pat. No. 4,039,472which issued Aug. 2, 1977 to Glen R. Hoff. The reference discloses thatMg(OR)₂ --Ti(OR)₄ can be contacted with one of EADC, EASC, etc., atabout 20°-70° C. and the resulting solid product can be treated with dryHCl at about 20°-70° C. to produce a catalyst. The results show thatcatalyst productivity is higher and the quantity of coarse polymerparticles is lower when Mg(OR)₂ --Ti(OR)₄ is contacted at about 25° C.with EADC. When the contacting occurs at about -20° C., catalystproductivity is reduced about 50% while the amount of coarse polymer issubstantially increased.

In comparing invention runs 2 and 5 and in view of control runs 1 and 4,the following conclusions can be inferred. The invention catalyst usedin run 2 is considerably more active than the control catalyst used inrun 1 although each catalyst produces about the same ratio of coarsepolymer of total polymer produced. The results of invention runs 2 and 3demonstrate that the activity of the catalyst is diminished when a TiCl₄treating temperature of 100° C. is used rather than a 25° C. treatingtemperature. However, the quantity of coarse polymer is substantiallyincreased by the higher catalyst treating temperature.

In comparing invention run 5 with control run 4 it is apparent that theinvention catalyst is much higher in activity but that it produces alesser amount of coarse polymer. The amount of coarse polymer producedby the invention catalyst can be substantially increased over that ininvention run 3 by a combination of a -25° EADC contacting treatment anda 100° C. TiCl₄ treatment. However, catalyst activity is decreased.Optimization of the treating conditions should afford inventioncatalysts demonstrating good activity as well as the capability forproducing good yields of coarse polymer.

Microphotographs of the polymer particles produced in control run 4 andin invention run 5 show that the polymer produced with the inventioncatalyst is essentially solid in nature. In contrast, the polymerproduced with the control catalyst appears to be a tangled mass of smallstrands. The catalysts produce polymer particles basically different inappearance and each catalyst therefore differs from one another in somesubtle fashion.

I claim:
 1. A polymerization process comprising contacting at least onealiphatic mono-olefin under polymerization conditions in the presence ofa catalyst which is formed by(1) mixing together a first catalystcomponent comprising a metal hydrocarbyloxide compound having theformula M(OR)₂) where M is a metal selected from Group IIA and Group IIBof the Mendeleev Periodic Table and R is the same or different and is ahydrocarbyl group having from 1 to 20 carbon atoms and a transitionmetal hydrocarbyloxide compound in which the transition metal isselected from the group consisting of Group IVB and Group VB transitionmetals of the Mendeleev Periodic Table and wherein the hydrocarbyl groupis as defined above in a molar ratio of transition metal compound tometal compound ranging from about 2:1 to about 1:2, (2) heating thefirst catalyst component solution formed in (1), (3) cooling the firstcatalyst component solution to a temperature below about 25° C. andoptionally filtering the first catalyst component solution to remove anyundissolved material from the cooled first catalyst component solution,(4) adding a precipitating agent comprising a second catalyst componentin a molar ratio of transition metal compound to the precipitating agentwithin a range of about 2:1 to about 1:3 to the cooled first catalystcomponent solution which is at a temperature ranging from about -50° C.to about 25° C. under conditions so as to avoid a significanttemperature rise in the solution and to produce a solid catalyst in theform of a slurry with the solvent, said second catalyst componentcomprising an organoaluminum halide represented by the formulas

    R Al X.sub.2

    R.sub.2 Al X, and

    R.sub.3 Al.sub.2 X.sub.3

wherein each R in the above formulas is as defined before and each R canbe the same or different, and X is a halogen atom, (5) washing anddrying the solid catalyst component thus formed and contacting same witha transition metal halide ion exchange source selected from titaniumtetrachloride, vanadium oxychloride (VOCl₃), and zirconium tetrachloridein a weight ratio of transition metal halide to said solid catalystcomponent ranging from about 7:1 to about 1:4, (6) separating the solidcatalyst component formed in (5) and washing same, and, (7) combiningthe washed and dried solid catalyst component separated in (6) with acocatalyst component comprising an organoaluminum compound.
 2. A processaccording to claim 1 wherein the polymerizable compound comprises atleast about 90 weight percent ethylene.
 3. A process according to claim1 wherein said polymerizable compound is essentially ethylene.
 4. Aprocess according to claim 1 wherein the polymerization temperature iswithin the range of about 50° C. to about 120° C., the partial pressureof the polymerizable compound is within the range of about 0.5 MPa toabout 5 MPa (70-725 psig).
 5. A process according to claim 1 furthercomprising a cocatalyst which comprises at least one organoaluminumcompound represented by the general formulas

    R"'.sub.3 Al,

    R"'AlX.sub.2,

    R"'.sub.2 AlX, and

    R"'.sub.3 Al.sub.2 X.sub.3

wherein R"' is individually selected from linear and branched chainhydrocarbyl radicals containing from 1 to about 20 carbon atoms forradical and each R' can be the same or different and X is a halogenatom.
 6. A process according to claim 1 wherein the catalyst is formedfrom magnesium diethoxide (1), titanium tetrabutoxide (2), andethylaluminum dichloride (precipitating agent), and the halide ionexchanging source is titanium tetrahalide.
 7. A process according toclaim 6 further comprising a cocatalyst which is triethylaluminum.
 8. Aprocess according to claim 1 wherein the resulting catalyst formed in(4) is contacted with a halide ion exchange source selected fromtitanium tetrachloride, vanadium oxychloride (VOCl₃), and zirconiumtetrachloride in a hydrocarbon diluent at a temperature within the rangeof about 0° C. to about 150° C.
 9. A process according to claim 8wherein said first and second catalyst components are formed frommagnesium diethoxide, titanium tetra-n-butoxide, and ethylaluminumdichloride, and the halide ion source is titanium tetrachloride.
 10. Aprocess according to claim 9 wherein the polymerizable compound isethylene and the catalyst further comprises a triethylaluminumcocatalyst.
 11. A process according to claim 1 comprisingcontactingethylene under polymerization conditions with a catalyst which forms onmixing a first catalyst component and a second catalyst component,wherein the first catalyst component is formed by mixing magnesiumdiethoxide and titanium tetra-n-butoxide, wherein said second catalystcomponent is ethylaluminum dichloride, wherein the catalyst is treatedwith titanium tetrachloride, and wherein said contacting is carried outemploying a triethylaluminum cocatalyst.
 12. A process according toclaim 11 wherein the first and second catalyst components are mixed at atemperature within the range of from about -50° C. to about 25° C. andthe resulting catalyst is treated with titanium tetrachloride at atemperature within the range of 0° C. to 150° C.